This invention generally pertains to exercise devices for recreational purposes. More specifically, the present invention relates to a roller ski for training long distance skiers.
The invention is particularly applicable to cross country skiing utilizing a skating technique called the "free technique." However, it will be appreciated by those skilled in the art that the invention has broader applications and may also be adapted for use in other roller ski environments or similar exercise environments as well.
A variety of sports have centered around devices which enable a person to travel rapidly across a ground surface using low friction devices mounted on his feet. Examples of such sports are ice skating, snow skiing, roller skating, and most recently, skate boarding.
Training systems for snow skiing require a device which can be used in a non-snow environment for wide and year-round application. A wheeled device is ideal for practicing on dry ground. Thus, roller skis have become well known aids for training in downhill skiing and cross country skiing when snow is not available.
Cross country skiing has been practiced in Northern countries for many hundreds of years and has recently gained popularity in the U.S. Due to the climate in this country, the cross country skiing season is generally rather short, lasting about four months. Since cross country skiing requires great stamina and good physical condition, it is advantageous for an individual who wishes to participate in this sport during the winter months to practice the basic cross country striding techniques during the off season. To accomplish the striding motion, cross country skiing utilizes a foot plate with a binding means adapted to retain the user's ski shoe in such a manner that its heel portion is freely pivotable about a firmly fixed toe portion.
Over the last two or three years, cross country skiing has split into two disciplines. The first of these is the traditional technique now called "classical" which includes the subclasses of the diagonal stride, herringbone, and double pole techniques. In a "classical" cross country ski race, a skating motion is prohibited. The classical cross country skis are waxed with a cross country wax for kick on the uphills and the traditional kick and glide stride is used. The skier stops each foot alternately, sets the wax, and pushes off. The motion is similar to running except that a glide phase is incorporated.
The second cross country skiing discipline is a new skating-like technique called the "free technique." This motion is similar to ice skating in that the skier drives off the gliding ski. The resultant track is a series of elongated V-like tracks in the snow. As the skier comes to the end of the glide phase, his ankle rolls to the inside which sets that ski on edge and provides a bite of that ski in the snow. From this, the skier is able to drive off on his other ski. At no time does the ski stop and thus no kick wax needs to be used. This results in a faster skiing technique and faster racing times.
Numerous roller skis for practicing skiing techniques are available on the market. All of these attempt to simulate the skiing stride, generally on a paved surface so that a skier is able to exercise the skiing motion during the summer months. Despite the fact that roller skis have been available for quite some period of time, the conventional roller skis have been only partially successful.
Roller skis which are designed to simulate the classical techniques of cross country skiing are generally of the three wheeled design such that two wheels are provided in the back and one in the front. A ratchet is provided on one or more of the wheels to simulate the setting action of the wax.
Roller skis for simulating the skating action of the free technique of cross country skiing are also known. Such skis are of the two wheel design with wide tires in both the front and the back so that the ski can be rolled slightly to edge and push off. However, such conventional roller skis are unable to provide a good edging action because when edging is attempted, the frame of the roller ski contacts the ground surface. Moreover, the conventional roller skis have a relatively high platform which makes the ski less stable.
Another difficulty with conventional roller skis has been the necessity of using a fork or wishbone-shaped bracket structure to support each wheel. This complicates manufacturing and increases the weight of the exercise device. Additionally, conventional roller skis do not provide tires which have been found suitable for adequately simulating the cross country skiing techniques which were attempted to be practiced.
Accordingly, it has been considered desirable to develop a new and improved roller ski which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.